In the art of spare tire lift units for motor vehicles and of the general type disclosed in U.S. Pat. Nos. RE33,303 and No. 4,969,630, the disclosures of which are herein incorporated by reference, it is desirable to minimize the size and weight of the tire lift unit in addition to simplifying its construction and assembly and thereby minimize its cost. It is also desirable to construct the unit so that when the tire lift cable is fully retracted and wound on the spool, the mechanical drive system for rotating the spool prevents backup of the spool, so that the spare tire is held firmly against the underneath side of the motor vehicle body even during substantial vibration of the vehicle. It has also been found desirable to provide the tire lift unit with one way coupling means which permit quick winding of the cable on the spool and retraction of the spare tire to its elevated stored position with the aid of a power driven tool. This minimizes the time required to assemble a spare tire onto a motor vehicle during original assembly of the motor vehicle, but prevents the tire from being removed without the use of the crank.